There is no need to adjust the speed of the fans yourself; the controller does it for you. When you first switch the controller on it will scan your room and calculate exactly how fast your fans need to run to maintain the temperature set, from that point on your room will remain at your desired temperature day in day out without you having to lift a finger.
The Twin Controller does not just simply shunt the fans from an idle speed to full speed after the temperature is exceeded, but adjusts the speed smoothly, and only by as much as is needed to keep the temperature constant. This new approach is far more accurate, limits fan noise and keeps your system working quietly and efficiently.
The Twin Controller is really simple to use and requires no wiring. Simply plug in your extractors, set the temperature you wish your grow room to be, the minimum and maximum speed settings and the Twin Controller will take care of the rest.